Just when we were still reeling from one catastrophe, along comes another. I’m talking about the nightmare last week in Las Vegas and the terrible death and destruction of this week’s Wine Country wildfires.

Superstar rock guitarist Joe Satriani is the subject of a documentary, “Beyond the Supernova,” shot and directed by his son ZZ. (Photo by Joseph Cultice)

Those of us fortunate enough not to be victimized or threatened by the rampaging blazes have been worried about friends and family and the thousands of people who have had to flee for their lives, not knowing if the home they left behind would be there when they get back.

I interviewed star rock guitarist Joe Satriani and his 25-year-old son, ZZ, one morning this week about “Beyond the Supernova,” a documentary ZZ made about his dad that has its world premiere Saturday at the Mill Valley Film Festival.

Satriani lives in San Francisco, where black ash from the fires was falling like evil snow. Before we talked about the film, he told me how concerned he was about his Sonoma County friends and colleagues, especially his manager, who had to evacuate his Santa Rosa home at midnight Monday.

“I’ve been trying to keep track of all my friends who live up there,” he says. “It’s devastating.”

In a dark week for the North Bay, the documentary is a bright spot for Satriani and his legions of fans. It’s debut screening will be followed on Saturday night by a sold out concert at Sweetwater Music Hall, the first time the virtuoso guitarist has played the Mill Valley club.

Out of dad’s shadow

ZZ embarked on his documentary project after graduating from Occidental College in Los Angeles in 2015 with a degree in art history and visual arts. But first he had to get over what a lot of celebrity offspring have to overcome – being in the shadow of a superstar parent.

“For a while before this, I didn’t want to do anything related to Joe,” he says. “I wanted to do my own thing. But I think I got to the point where I didn’t really care anymore about the shadow thing.”

The documentary evolved from a series of short web videos ZZ shot of his dad and band into a full-blown chronicle of their recent “Shockwave” tour through Asia and Europe on the 30th anniversary of his career-making album “Surfing with the Alien.”

In between scenes of good-natured backstage banter between Joe and his bandmates, ZZ weaves in the background story of his dad’s life and career. It begins with young Joe hearing that his idol, Jimi Hendrix, had died, and deciding to follow in Hendix’s footsteps as a superstar rock guitarist.

Early on, he had to learn to balance stage fright and performance anxiety with the thrill of playing for a live audience.

“I was able to dig out this photo that someone had taken of me at my very first performance in my high school gym,” Satriani says. “I had my back to the audience I was so petrified. But I remember thinking that was the most fun I’d ever had. And I knew that was what I was going to do for the rest of my life even if I was nervous.”

Stardom came relatively late for Satriani. Growing up on Long Island, he began teaching guitar while studying music at a local college. One of his students, Steve Vai, who went to the same high school, would go on to win three Grammys and be voted 10th on Guitar World magazine’s list of Greatest Guitarists. In the film, he shows up on stage for Satriani’s 60th birthday celebration, and the two old friends shred together in a scintillating duet.

Guitar guru

After moving to Berkeley in the late ’70s to launch his career in music, Satriani ended up spending 10 years teaching guitar in the back of a music store, becoming a guitar guru for serious young players like Metallica’s Kirk Hammett, Alex Skolnick of Testament, Larry LaLonde of Primus, Third Eye Blind’s Kevin Cadogan, David Bryson of Counting Crows and the seven-string guitar master Charlie Hunter.

“I spent 50 hours a week teaching,” he recalls. “I was overwhelmed by the amount of people who wanted to take lessons from me. I was blessed with amazingly driven young kids creating the next wave of music. It made it exciting.”

It would be Satriani, though, who would create the next wave of music for rock guitarists in 1987 with “Surfing with the Alien,” his platinum-selling breakthrough album. The irony was that his record company wasn’t sure if it was going to release the all-instrumental record. When it did, Satriani’s radio hits caught the ear of the Rolling Stones’ Mick Jagger, who hired him as the lead guitarist in his first solo band.

Satriani was turning 30 then, hardly making him an overnight success. But going from being an unknown Berkeley guitar teacher to playing sports stadiums with a superstar like Jagger took some getting used to.

“It’s shocking how things can take you by surprise,” he says. “I suddenly realized that I wasn’t prepared to stand next to somebody like Mick Jagger, who knows how to handle this stuff. Suddenly, with all those eyeballs on you and people asking questions, it requires you to brace yourself and take a deep breath whenever you’re in public.”

In his own shows, Satriani developed a persona, a character to hide behind that he calls Shockwave. It became more pronounced after he began losing his hair and shaved his head. Dark glasses and a hat rounded out the new look.

“My band was laughing about it, but what I noticed was that the audience reacted very strongly to the fact that I didn’t come out like I usually did,” he says. “It made a bold statement to the audience, but, for me, it was a nice little curtain that I could hide behind. It made the experience of stepping out on stage less traumatic. At the same time, it allowed me to be more expressive musically.”

Cathartic process

After decades in the spotlight, Satriani has traveled the world as a headliner and as the founder of his “G3” guitar extravaganza with other master shredders, including Vai and John Petrucci. His many studio recordings and live albums have sold more than 10 million copies, including two platinum and four gold albums. He’s been nominated for Grammys 15 times, and he’s had success in a side project, Chickenfoot, with former Van Halen frontman Sammy Hagar.

In the documentary, there are indications at this mature point in his career that Satriani may have outgrown his Shockwave character.

“During the making of the film, ZZ uncovered that it was in fact weighing on me toward the end of the tour,” he says. “He was right there to witness me going through that. As ZZ’s film sets up, it’s the result of me saying I’ve got to cut ties in a certain degree to the past and return to an essential part of my musical being. It was an interesting cathartic process.”

On his new album, set for release in January, Satriani dispenses with tunes about science fiction, time travel, aliens and faraway planets.

Instead, he’s recorded what he calls “a real rock and soul record.”

“That’s what I was looking to do, and that’s return to my most basic musical influences,” he says. “And to have the film be an introduction to this new musical direction is an interesting way to bring out an album.”